When a user is entering characters on a terminal device with a touch screen, such as a mobile phone, in addition to the handwriting input, the user may enter characters through a soft keyboard in related arts. One of the biggest problems for soft keyboard is that the user cannot accurately select and input the desired character through the soft keyboard. Therefore, the character selected by the keyboard is usually a character around the target character instead of the target character itself, and thus the user has to try to enter the target character again.
The size of each key may be increased by enlarging the screen of the terminal device to improve input accuracy. However, the screen size of the terminal device is limited after all and different people have different finger sizes, thus the above problems can't be fundamentally solved by enlarging the screen of the terminal device.